https://ir.cut.ac.zw:8080/xmlui/handle/123456789/14 2026-06-06T01:36:38Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/773 Is neutral genetic diversity related to quantitative variation in semen traits in bulls? Gororo, Eddington; Chatiza, Fungayi Primrose; Chidzwondo, Farisai; Marshall Makuza, Stanley Conservation decisions based on neutral genetic diversity have been observed to promote retention of useful quantitative variation in biological populations. An experiment was undertaken to determine the association between microsatellite marker polymorphisms and phenotypic variation in semen production and cryosurvival traits in bulls. Thirty-five ejaculates were collected from ten bulls of two breeds and evaluated before and after cryopreservation for several semen traits. The bulls were also genotyped using a set of sixteen bovine-specific microsatellite marker loci. Fixation indices (FST), heterozygosity and Nei's genetic distance measures were computed from allele frequency data for each of the bulls. Molecular and phenotypic data were used to compute tri-distance matrices for the ten bulls and correlated using Mantel's test in GenAIEx 6.5. The study revealed extensive heterogeneity in semen traits, heterozygosity and FST values among the bulls. Large pairwise phenotypic and genetic distances were also observed. Correlation between pairwise genetic distances and phenotypic distances was significant and highly positive for sperm viability (r = .61, p < .001) and moderately positive for sperm motility (r = .40–42, p < .05) variables. For sperm morphology, ejaculate volume and sperm concentration, correlation with genetic distances was positive, low and not significantly different from zero (p > .05). A tendency for a triangular-shaped relationship between genetic and phenotypic distances for post-thaw motility and viability traits was also observed. Accordingly, association with neutral genetic diversity was absent for semen production traits and moderate to highly positive for sperm cryosurvival traits. Given these findings, conservation decisions based on neutral genetic diversity may capture variation in some adaptive traits, but not others. 2021-05-01T00:00:00Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/337 Effect of whole and clarified egg yolk based extenders on post-thaw semen quality in bulls Kamusasa, Prosper; Gororo, Eddington; Chatiza, Fungayi Primrose This study was conducted to evaluate the comparative cryoprotective effects of whole egg yolk and clarified egg yolk on post thaw sperm quality parameters and to determine the optimum clarified egg yolk inclusion level (10-20%) in semen extenders for Mashona bull semen cryopreservation. It was shown that there was a significant decrease in sperm quality variables following cryopreservation. Semen quality increased with the concentration of clarified egg yolk, indicating a positive relationship between egg yolk LDL concentration and maintenance of in vitro sperm quality. The 20% clarified egg yolk (CEY20) extender treatment gave post-thaw motility, viability and normal morphology values which were comparable to the control (20% whole egg yolk, WEY20). The 10% clarified egg yolk concentration gave the least post-thaw quality values and the greatest proportion of defective spermatozoa. This experiment found no advantage of replacing whole egg yolk with up to 15% clarified egg yolk in Mashona bull semen cryopreservation. However, 20% clarified and 20% whole egg yolk performed similarly in the maintenance of post-thaw sperm motility, viability and normal morphology. 2021-05-21T00:00:00Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/336 Use of RAPD-PCR for breed/genotype identification in Zimbabwean cattle Mhuka, Christine; Chatiza, Fungayi P.; Chidzwondo, Farisai; Sithole-Niang, Idah; Makuza, Stanley; Mlambo, Sibonani S . Lack of resources for characterization and the indiscriminate crossbreeding of cattle in Africa have led to the loss of some breeds. This study was aimed at screening for polymorphic primers for cattle breed identification in Zimbabwe. The Nguni and other local breeds have suffered genetic losses due to indiscriminate crossbreeding. Genetic characterization and semen cryopreservation are important in conservation and breeding programs. Genomic DNA was extracted from whole blood using a DNA extraction kit and was amplified using RAPD-PCR. A total of 8 primers was screened and five (OPX-15, OPB-04, 0PG-07, OPG-12 and OPD-02) were polymorphic and three (OPD-01, OPB-05 and OPB-09) were monomorphic, as revealed by agarose gel electrophoresis. RAPD-PCR was found to be effective in detecting the polymorphisms within the bovine species. The polymorphic primers can be used to determine genotype variations in crossbred animals to determine genotype variations in different breeds. 2017-01-01T00:00:00Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/335 The potential of reproductive technologies in breeding smallholder cattle populations in Zimbabwe Gororo, Eddington; Makuza, Stanley M; Chatiza, Fungayi P; Gwatibaya, Showman; Gahadzikwa, Passmore; Chidzwondo, Farisai Cattle are critical to most smallholder agricultural livelihoods in Sub-Saharan Africa. A study was carried out to assess breed and trait preferences, breeding practices, application and potential adoption of novel reproductive technologies by smallholder cattle farmers in four districts of Zimbabwe. The study revealed that famers are subsistence oriented and follow a resource driven production system. Herd size averaged 7.5±6.42, with dominance of indigenous breeds and their crosses, open communal breeding and non-existence of reproductive technology application. The major challenges faced include reproductive and tick-borne diseases, dry season feed shortage, and poor access to affordable good quality bulls. Brahman, Mashona, Afrikaner and Tuli were the most preferred breeds for their hardiness, fertility, reproductive efficiency and draught performance attributes. Low reproductive efficiency was revealed by long bull retention periods (>5 years), long calving intervals (>18 months), low pregnancy rates (41% of cows) and high ages at first calving (34 months). Farmers indicated moderate knowledge of artificial insemination and keen interest in using this technology with semen frozen from locally bred, indigenous sires to improve their herds. There is therefore both need and potential for the application of assisted reproduction techniques for improved genetic gain, performance and reduced inbreeding in smallholder cattle herds. 2017-08-17T00:00:00Z